The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 15, 2008
Filed:
Jul. 11, 2006
Yasuo Hirata, Chita-gun, JP;
Akihiro Okamoto, Hashima-gun, JP;
Keiji Wakahara, Inazawa, JP;
Denso Corporation, Kariya, Aichi-pref., JP;
Abstract
A target air-fuel ratio setting part has a sub-feedback part, a target air-fuel ratio enriching part, and a target air-fuel ratio changeover part. The sub-feedback part variably sets a target air-fuel ratio upstream of a catalyst on the basis of a detection signal of an O2 sensor provided downstream of the catalyst. The target air-fuel ratio changeover part uses, as the target air-fuel ratio, a rich target air-fuel ratio which is set by the target air-fuel ratio enriching part on conditions such that the target air-fuel ratio set by the sub-feedback part is rich. A cylinder-by-cylinder air-fuel ratio estimation part calculates a cylinder-by-cylinder air-fuel ratio on the basis of a detection value of an air-fuel ratio sensor and the target air-fuel ratio.